63-64 Corvette Type I Jack Bearing Question

[David L.]

I am looking for a "correct" replacement bearing for a 1963-1964 Type I jack. I bought the jack at a swap meet many years ago and the bearing was missing. According to my notes from the January 1992 Cypress Garden swap meet I measured the bearing on an original 1963 jack. The thrust bearing was stamped "IRWIN BRG. CO. CINC. OHIO" and "H-2 TOP". The width of the bearing measured 3/8" and the circumference of the bearing measured about 4.0" +/- which would make the outside diameter about 1 1/4". Is the "correct" bearing size 1/2" I.D., 1 1/4" O.D., and 3/8" wide? I have found thrust bearings on the web that measure 1/2" I.D., ! 1/8" O.D., and 3/8" wide as well as 1/2" I.D., 1 3/8" O.D., and 7/16" wide.

The 1/2" diameter shaft length on my Type I jack measures 14 3/4" long with the thread length measuring 8 1/2". The available space between the 3/4" hex nut and the pin hole where the 3/8" wide thrust bearing would be located measures about 25/32".
Dave

[Alan D.]

Re: 63-64 Corvette Type I Jack Bearing Question

Dave the bearing measurements look correct however my shaft is 15 3/4. The distance from roll pin to end of shaft 1 3/4 So it may be your shaft, but you will need to check
My thrust bearing has different markings.

[David L.]

Re: 63-64 Corvette Type I Jack Bearing Question

Alan,
Could the "early" type I jacks with the "A" stamping have a shorter shaft length?
The 7/64" steel pin (the hole measures about 0.11" or 7/64") on my jack shaft is also missing and that explains why the bearing is missing.
The distance from the threaded end of the shaft to the pin hole measures 13 1/8" and from the pin hole to the hex nut end measures 1 5/8" for a total of 14 3/4".
The reproduction Type I and II scissor jacks on the Long Island Corvette Supply website show a length of 14 7/8". I had assumed that 14 7/8" was the total length of the shafts on type I and II jacks. but maybe not (see link below).
Just a bit more confused.
Dave

jacks and handles_corvette.htm

[Alan D.]

Re: 63-64 Corvette Type I Jack Bearing Question

David,
Tried to sent you an email since NCRS was down, it's changed.

Have two jacks, believe the extra is from a 67, that measures 13" total length
from nut end the non screw is 4 1/2 with screw being 8 1/2 for the 13"
from nut end, large nut hole is 3/8 with a d= .191
from nut end, small hole is 1 3/4 with a d= .113


At some time GM changed the nut end to bend inward and also replaced the bearing, that change allowed a shorter screw (cost savings)
See Noland Adams page 103 Also the "Corvette Restorer" for 63/64 CD from NCRS has two articles in it
Now I recall that I had to replace my screw on the 64 jack, think I kept the correct length however would not swear to that.

[David L.]

Re: 63-64 Corvette Type I Jack Bearing Question

Alan,
I have the 63-67 restoration book by Noland Adams and all the Corvette Restorer magazines since I joined in 1980. The shop drawing on page 105 is of a Type III jack. The drawing shows the total length of the jack as 13.50"-14.00" which would make the long screw maybe 3/4" or so shorter for a 12 3/4" to 13 1/4" long screw which checks out with the long screw length of 13" on your 67 jack.

I also have a similar Type I Corvair scissor jack (without any stamping, possibly made by RH INC.) where the long screw measures 14 5/8". I guess that it is possible that the long screw in my Type I scissor jack (stamped "A") might have been replaced with a RH INC. long screw.
Hopefully someone else will chime in.
Dave